P-0 cell of urothelium of primitive bladder true P-0 cell of urothelium of primitive bladder (syn: transient urothelial progenitor cells) (TS:19-TS:21): a transient embryonic urothelial cell type of the primitive bladder. P-0 cells are defined by their expression pattern and location in the urothelium. P-0 cells express Shh, Uroplakin, Trp63, Isl1 and Foxa2. P-0 cells do not express Krt5. They make up most of the TS:19-20 urothelium and generally reside on the luminal surface of the urothelium at TS:21. P-0 cells are the progenitors of intermediate cells and superficial cells of the urothelium of primitive bladder/bladder during embryonic development. EMAPA:36087 anatomical_structure